The present invention relates generally to a wheeled stretcher having a bed surface and a supportive base typical of those used in hospitals. More particularly, the invention relates to means by which the bed surface of the stretcher may be moved from a flat, horizontal position to an inclined Trendelenburg or reverse Trendelenburg position.
Various types of bed-like equipment are commonly used in hospitals and other health care facilities. One type of such equipment is referred to as a stretcher, normally provided with wheels for ease of movement, and used in a variety of situations. For example, the wheeled stretcher may be used in emergency room settings, as well as in general hospital service for transporting patients from one location to another. Such a stretcher is of relatively heavy-duty construction, and includes a base supported by a plurality of wheels, the base in turn supporting the stretcher frame to which a bed portion is attached. The stretcher is also normally provided with side rails which may be selectively raised or lowered. The rails securely hold the patient on the stretcher, but can also be moved out of the way to enable the patient to move or be moved from or onto the stretcher.
Particularly when used in the emergency room, the wheeled stretcher fulfills a variety of rolls. For example, it may serve as a bed during a period of time when a patient is awaiting treatment. It can be used to transport the patient, and properly equipped, may be used as an X-ray table. Frequently, the stretcher also serves as the examination table, or even as a surgical table, for treatment of the patient.
When used as an examining table, whether in an emergency room or other setting, the stretcher may require movement from a flat, horizontal position to an inclined position. Such positions are used with some frequency in performing common medical procedures. Movement of the stretcher to a position wherein the patient's feet are raised with respect to the head is known as a Trendelenburg position. Where the patient's head is elevated with respect to the feet, the position is referred to as a reverse Trendelenburg position. In each case, movement of the stretcher to such a position requires that the bed surface remain planar, while it is piovted with respect to the stretcher base.
One known manner in which a stretcher is constructed for movement to the Trendelenburg and reverse Trendelenburg positions includes pivotally mounting the bed-supporting frame to the base. The base and frame are further connected by a gas spring. The spring includes a piston having a valve means for locking the piston into position within the spring housing. An actuation means is provided for releasing the piston for movement. Upon movement of the actuator, the spring is unlocked, and the stretcher frame may be pivotally moved by hand either upwardly or downwardly as desired. The spring provides a counterbalancing force so that the full weight of the stretcher frame is not felt by the operator in moving the frame. After release of the actuator, the gas spring locks and forms a rigid connection between the stretcher frame and base, holding the frame in its selected angled position.
The gas spring actuator is typically operated for extension or retraction by a handle located near one end of the stretcher. Pulling or pushing on this handle is then simultaneously used to move the frame into its desired angled position. However, no stop device or other indication is provided for identifying the normal, horizontal position for the stretcher. When returning the stretcher to the normal position, it may take several movements of the frame to place it into the proper position. Further, movement of the handle enables the stretcher to be moved either upwardly or downwardly, so that it is entirely possible that the stretcher may inadvertently move in a direction other than that desired. These problems are particularly significant in an emergency room setting, where the primary attention of the hospital personnel must be on the patient rather than manipulation of the stretcher.
What is needed therefore, is a control means for the angular adjust mechanism for a wheeled stretcher. The control means must enable the operator to easily find the normal position for the stretcher, as well as ensuring that the stretcher is moved in the desired direction. The control must not require complicated or cumbersome actions on the part of an operator, and should be generally similar to actions required with controls presently in use. At the same time, the control means must be relatively simple, so that it will act reliably and may be added to the stretcher assembly without unduly increasing either cost or complexity.